<!DOCTYPE html>
<html>
  <head>
    <link rel='stylesheet' type='text/css' href='reference-style.css'>
    <style>
      body > button:nth-child(1) > .input-color-swatch { background-color: #000000; }
      body > button:nth-child(2) > .input-color-swatch { background-color: #000000; }
      body > button:nth-child(3) > .input-color-swatch { background-color: #00ff00; }
      body > button:nth-child(4) > .input-color-swatch { background-color: #123456; }
    </style>
  </head>
  <body>
    <button class="input-color">
      <div class="input-color-swatch">
      </div>
    </button>

    <button class="input-color">
      <div class="input-color-swatch">
      </div>
    </button>

    <button class="input-color">
      <div class="input-color-swatch">
      </div>
    </button>

    <button class="input-color">
      <div class="input-color-swatch">
      </div>
    </button>
  </body>
</html>
